Print Fan Error
Prusa i3 Mk3
Firmware 3.1.3
Print fan failure after less than 1kg of PLA.
I found the ground wire to the print fan broken internally about 3 inches from the fan itself. Replaced wire & repinned plug with new high quality type used to connect servos in radio control applications. The new wire is much more flexible, has about double the strand count and more durable.
PRUSA: The wire used to connect the print fan isn't suitable for this type of application. Its too brittle, and too low a strand count. It will break in time. I recommend sourcing a higher quality wire, as we're seeing failures of this cheap wire now.
Kind regards,
Bill Wightman
Re: Print Fan Error
I found the ground wire to the print fan broken internally about 3 inches from the fan itself.
That sounds exactly like where it would break if the strain relief (cable holder beam + nylon filament) wasn't right.
ie, right here (i know this is an mk2, just for illustration):
Re: Print Fan Error
I found the ground wire to the print fan broken internally about 3 inches from the fan itself.
That sounds exactly like where it would break if the strain relief (cable holder beam + nylon filament) wasn't right.
Yeah, its a bizarre place to fail. I took this pic of my Mk3 while disassembling for the fan wire replacement. The cable support arm and filament strain relief were assembled perfectly. The spiral wrap is taken off here to expose the fan wire for the picture:
The print fan wire (yellow/red/black) is clearly visible in this shot. Everything was assembled exactly per Prusa's instructions, and done BETTER in many areas.
This was simply a case of cheap wire failing internally. It won't be a problem any more!